CN102713058A

CN102713058A - Calender for smoothing a paper web

Info

Publication number: CN102713058A
Application number: CN2010800295898A
Authority: CN
Inventors: P.斯文卡; B.布伦德尔; E.达维丹科
Original assignee: Andritz Kuesters GmbH
Current assignee: Andritz Kuesters GmbH
Priority date: 2009-06-30
Filing date: 2010-06-25
Publication date: 2012-10-03
Also published as: PL2270279T3; EP2270279A1; WO2011000530A2; EP2270279B1; JP2012531536A; WO2011000530A3; CA2765128A1; ATE541987T1; US20120103552A1; US8440054B2

Abstract

The invention relates to a calender (1) for smoothing a paper web (2), in particular made of paper capable of gravure printing, comprising at least one roller stack, each roller stack comprising an upper and a lower end roller (4.1, 4.2) and intermediate rollers (5.1, 5.2, 5.3, 5.4), wherein one of the two end rollers (4.1) bounds a first working gap (3) of the roller stack depending on the guiding of the paper web (2), and the rollers (4.1, 4.2, 5.1, 5.2, 5.3, 5.4) are hard rollers (4.1, 5.2, 5.4) and soft rollers (5.1, 5.3, 4.2) in order to form loadable working gaps in the form of soft nips, wherein the end roller (4.1) bounding the first working gap (3) is a hard, heatable roller, the diameter of which is greater than the diameter of a hard, heatable intermediate roller (5.2, 5.4) and the outer wall (9) of which forms one of two contact surfaces (9, 10) of a web treatment gap (8); arranged upstream of the first working gap (3), and the other contact surface is formed by a belt (14) circulating on guide rollers (11, 12, 13).

Description

The calender that is used for smooth paper web

Technical field

The present invention relates to a kind of by claim 1 as described in the preamble be used for smooth paper web, the calender of the paper web especially processed by the paper that can supply intaglio printing.

Background technology

For improving surface quality, carry out smooth to paper web.Can supply the paper of intaglio printing to belong to high-quality paper, require extra high fineness.Disclose a kind of calender that is used to handle paper web by EP0886695B1, it has a plurality of rollers, is forming as the soft roll gap working clearance, so-called between a hard roller and a soft roller respectively.A plurality of working clearances (roll gap) have realized good printing effect is had best bright finish value smooth of decisive role.

Yet, during online at high speed or off-line operation, must select high temperature at machine for this reason.High temperature can cause the paper surface keratinization, and this is brushed with adverse influence to intaglio process.In addition, when high temperature, the roller surface of heatable roller discharges excessive heat loss to environment.

Summary of the invention

Therefore, technical problem to be solved by this invention is, creates a kind of calender, and this calender can carry out highly smooth and can practice thrift cost and the operation of conserve energy ground at this paper web.

This technical problem solves through the characteristic of claim 1.

Created a kind of calender thus, wherein, paper web is getting into first working clearance (roll gap) before through a preliminary treatment path, is used in the intervals of business (roll gap) and produces best temperature when smooth and distribute.When moisture can be selected, the roll surface temperature of the heatable roller of roller stacking only need be selected slightly highlyer than the plasticization temperature of corresponding paper web for this reason.For example can be so that only high 10-30 ℃ roll surface temperature is smooth in the intervals of business.

Compare end rollers hard, that heatable intermediate calender rolls diameter is bigger, that limit the first roll gap border respectively and realized handling the such structure in path, this length of handling the path is bigger than roll gap length.In the multiple roll crack calender that has the soft roll gap of soft roll gap and prolongation (wide roll gap), realized the lifting of smooth effect thus.This is particularly suited for SC-A, SC-B and LWC paper.Practiced thrift energy by the heat radiation of heatable roller minimizing and the forced convertion of minimizing.Also improved the efficient of hot transmission, because reduced the degree of heat loss.

The holdup time coupling collar that in breadth is handled the gap, prolongs around the surface of band preferred elastomeric, obviously improved heating to paper web.Guaranteed good heat transmission,, made and to have avoided as far as possible because the mattress that the paper web injustice causes that this mattress can hinder heat transmission because paper web is pressed on the heatable roller equably.The delay path that the advantage of the calender of being advised also is used to heat breadth by prolongation combine to form around band obtain, this band is the working clearance of process roller stacking before paper web directly.

Can equably paper web be heated to technical required degree through prolonging the heating of paper web in breadth processing gap.To this, roll surface temperature is just enough in 80 ℃ to 160 ℃ scope usually.In order to help to prolong the time of temperature action, reduce the height of temperature.The temperature of heat-mechanical planarization process reduces then only to be confirmed through the plasticization temperature and the moisture thereof of employed sheet fiber basically.The surface of band preferred elastomeric guarantees uniform pressure and therefore guarantees to transmit to the even heat of paper web from the roller of heating at this.

Pressure is preferably regulated through the stress of band.The tangential stress of band to usually by plastics, rubber, the loading that scribbles the carrier material of plastics or scribble the band that the carrier material of rubber processes usually much smaller than radial stress.Stress radially makes plastics be layered as laminated composites.The thermal stress of band is lower, and therefore band has the long life-span.

Can cheapness and conserve energy ground realization while working pressure and the desired advantage of temperature and effect in roll gap in formation process through pressing calender of the present invention.

For realize depth of invasion that heat hopes required, can be through by means of compressing length optimization on the circumference of guide roller accommodation zone at heatable roller in the holdup time that breadth is handled in the gap.

Preferably can through the guide roller that is used in the endless belt extra as hold-down roller work regulate breadth and handle local pressure controlled in the gap and increase.

Draw other design structure of the present invention by following explanation and dependent claims.

Description of drawings

Followingly specify the present invention according to embodiment illustrated in the accompanying drawings.

Fig. 1 has schematically illustrated the calender by first kind of embodiment;

Fig. 2 has schematically illustrated the calender by second kind of embodiment;

Fig. 3 has schematically illustrated the calender by the third embodiment.

The specific embodiment

The present invention relates to a kind of calender 1 that is used for smooth paper web 2, said paper web especially is made up of the paper that can supply intaglio printing.Fig. 1 has schematically illustrated the calender by first kind of embodiment, and this calender has at least one roller stacking, and this roller stacking has upper end roller 4.1 and bottom roller 4.2 and intermediate calender rolls 5.1,5.2 respectively.Relevant along the guiding of traffic direction L with paper web 2, one of two end rollers are the borders that upper end roller 4.1 limits first working clearance 3 of roller stacking at this.The roller stacking comprises a plurality of rollers 4.1,4.2,5.1,5.2, and said roller can be loaded for formation, form is the working clearance of soft roll gap to be designed to hard roller 4.1,5.2 and soft roller 5.1,4.2.The end rollers 4.1 that limits first working clearances 3 border is hard, heatable roller, and its diameter is greater than the diameter of heatable hard intermediate calender rolls 5.2.The outer wall of end rollers 4.1 also forms the breadth that is arranged in first working clearances 3 front and handles a contact-making surface 10 in gap 8.Another contact-making surface 9 that breadth is handled gap 8 is by being looped around

guide roller

11,12, is with 14 to form on 13.Therefore, be provided with two contact-making surfaces 9,10, said contact-making surface forms the processing path, the breadth that prolong and handles gap 8.

Breadth is handled gap 8 and is preferably extended along the angle that holds of heatable hard end rollers 4.1.Around with 14 on rubber-like surface towards the side of paper web 2.

Guide roller

11,12,13 controls be used for breadth handle gap 8 pressure-loaded paper webs 2 with 14 band stress.

The diameter of end rollers 4.1 that limits first working clearances 3 border is between 1.2m to 2.0m.The diameter of heatable hard intermediate calender rolls 5.2 is in 0.6 to 1.2m the scope.End rollers 4.1,4.2 preferably is used for regulating simultaneously the deflection dancer rools of breadth 2 along horizontal profile.All rollers 4.1,4.2,5.1,5.2 preferably have own analog line driver.The roller of roller stacking is stacking vertically, flatly or obliquely.

The roller stacking can be through at least one distolateral load cylinder and/or through acting on roller 4.1,4.2, and the independent load elements on 5.1,5.2 loads, through corresponding specific electric load in the said load elements scalable working clearance.Calender can online or off-line ground use.

Regard as soft roller or as have elastic webbing boots formula roller the roller type and decide, the roll gap length of soft roll gap 3 is preferably in 3 to 40mm scope.Heatable end rollers 4.1 is for example according to the plasticization temperature of corresponding paper web 2 and the roll surface temperature that moisture is heated to 80 ℃ to 160 ℃ thereof.

Contact-making surface 9 is contact-making surfaces of annular, and this contact-making surface is through being looped around

guide roller

11,12, is with 14 to form on 13.Another contact-making surface 10 is formed by the annular outer wall of heatable hard roller 4.1.Breadth is handled gap 8 and is extended along the angle that holds of heatable roller 4.1.Handle the length in gap 8 in order to change breadth, can hold the angle according to the hope depth adjustment that heat invades in the paper web 2.On the circumference of heatable end rollers 4.1, compress length through accommodation zone 14, by means of

guide roller

11,12,13 have optimized the optional holdup time.The length that compresses on the circumference of roller 4.1 is preferably regulated between 0.25 to 5.0m changeably.

Around be with 14 paper web 2 to be pressed on the heatable roller 4.1 with elastic surface, be used to improve the thermal efficiency that heat is transmitted.

The pressure that breadth is handled in the gap 8 can be regulated through the stress with 14.Maximum tension stress with 14 is preferably limited to 200kN/m.The attainable compression of pretreating zone of handling gap 8 at breadth for example can be assumed in the scope at 0.01MPa to 0.5MPa.This is relevant with heatable end rollers 4.1 selected sizes with band stress.

Breadth 2 can surround heatable end rollers 4.1 along part portion section before entering into breadth processing gap 8.

The surface temperature of heatable end rollers 4.1 is preferably by such adjusting, makes in the holdup time of breadth 2 to reach below with 14 for the glass transition temperature in the best depth of invasion of the respective objects of formation process.The depth of invasion of about 10 μ m is enough to be used in the smooth of height.Optimize breadth like this and handle the surface temperature and the length in preliminary treatment path in gap 8, make it possible to, the glass transition temperature of the not obvious surf zone to be plastified of this temperature above breadth 2 with such temperature operation.Pretreated like this breadth 2 can be used nozzle and/or seam humidifier wetting before calender 1 in advance, and this breadth is directly smooth in roll gap 3 and follow-up roll gap the preliminary treatment path after.Roll gap 3 directly is arranged on the heatable end rollers 4.1 after the portion's section that holds.If technical needs also can be perhaps wetting between two calenders 1 after calender 1.

Around be with 14 preferred rubber-likes surface, be used to guarantee uniform pressure, this pressure can be regulated through the stress with 14.Handle environment heat shielding gap 8 to the heat transmission of paper web 2 through the belt passing round 14 relative breadths of design like this from the end rollers 4.1s of heating.Heat is improved to the introducing in the paper web 2, because reduced the discharge of heat to environment.If elastic surface is an insulator, so further improved the introducing of heat to paper web 2.Around therefore preferably be less than or equal to 10W/mK with 14 elastic surface by thermal conductivity, especially be less than or equal to 5W/mK, the material that especially preferably is less than or equal to 1W/mK is processed.The hardness of elastic surface is preferably spent to the scope of shore hardness D92 degree at shore hardness A 50.

Preferably processed by flat carrier material with 14, this carrier material is provided with one or more flexible coatings.Can use high-intensity plastic optical fibre, glass fibre or carbon fiber as carrier material.These composites have high tensile strength.In order to improve the mechanical strength of band, also can add supporting fabrics or the supporting strap processed by aforesaid fiber.Around can also process by the carrier material that is equipped with elastic coating with 14, wherein, carrier material also can be processed by metal or metal tape.The hardness of metal when elastic layer is enough thin, can be used for smooth paper web 2 towards the endless belt that side of 14.The roughness of the elastic surface with 14 is preferably in the scope of 0.5 to 5 μ m.The fineness that elastic surface with 14 obtains then can convert the fineness on the paper web 2 into.For example have heat-resisting face coat with 14, this face coat is for example processed by silicon.Heat-resisting coating provides high scuff resistance and even curface.

The preliminary treatment path that breadth is handled gap 8 especially also is used for preparatory smooth breadth 2.

Around also preferably only have little expansion with 14, this expansion is less than or equal to 7%.Then, during the band stress in accommodation zone 14 because the expansion that the tension in 14 occurs is not disturbed smooth.Have at least the width identical with 14 with breadth 2.Thickness with 14 and its width and length is relevant and can be between 4 to 20mm.

At least one

guide roller

11,13 can be designed as pressure roller, and the breadth 14 that this pressure roller is handled breadth in the gap 8 compresses through extra radial pressure load on traffic direction L along portion's

section.Guide roller

11,13 preferably is designed to pressure roller at the inlet and/or the outlet side in breadth processing gap 8.At this, on the contrary radial pressure load can entrance side set than outlet side low or.This pressure roller can be the deflection dancer rools.

Fig. 1 shows calender 1, wherein, is with 14 to twine heatable hard roller 4.1 greater than 60 degree.Holding the angle preferably spends between 270 degree 60.Around continuous belts 14, also be called as belt, through three

guide rollers

11,12,13 in a ring around 4.1 guidings of heatable roller.Be with 14 at this through guide roller 12 tensionings.Confirm with 14 pressure on breadth 2 through this stress.Also cause the higher pressure of breadth 2 and help smooth breadth surface with 14 higher stress, that is smooth in advance.

And then and the roll gap 3 that forms through identical heatable roller 4.1 and finally smooth with the follow-up roll gap of 4.2 formation handle the breadth 2 handled in the gap 8 at breadth by roller 5.1,5.2.Specific electric load in these roll gaps can adapt with smooth effect to be achieved.Average compressive stress can be through the paper in the roll gap at 2N/mm ²To 55N/mm ²Between regulate.Compression in the upper area in said zone has realized high quality paper (like SC, LWC and MWC paper) or has not had the smooth of paper that wood pulp applies.Through directly compressing two rollers 4.1 and 5.1, rather than between these two rollers steering tape 14, can realize that accurate profile regulates.With 14 since the thickness difference that manufacturing tolerance or thermal expansion possibly exist smooth result is not exerted an influence.

Because the length in the temperature of the end rollers 4.1 of heating and the processing path that forms below with 14 is conditioned like this; Make that basically only the zone of the near surface of breadth 2 is heated; Handle the path so produced such one; Wherein, the inside of breadth 2 remains on plasticization temperature or below the glass transition temperature.Many times of the maximum unevenness that thickness breadth 2 near surfaces, that be placed in the above coating of plasticization temperature is paper surface.Therefore, the thickness of coating to be heated is relevant with the roughness of pending breadth 2.The length that breadth is handled gap 8 and breadth 2 have confirmed that along the speed of traffic direction L breadth 2 handles the holdup time in the gap 8 and therefore also confirmed the depth of invasion of heat in breadth 2 and be heated to the bed thickness of deformation temperature at breadth.

Bringing surrounding air in the boundary layer into through breadth 2 makes from the end rollers 4.1 of heating and transmits variation to the heat of breadth 2.Realized the obvious improvement of hot transmission through removing the boundary layer.Realized before the entrance side of breadth treating apparatus 7 in the contact path of adhering to contact between the outer wall that this for example can be through making heatable end rollers 4.1 and the surface of paper web 2.Also suitable is that the end rollers 4.1 that heats relatively compresses guide roller 11.Can push the boundary layer of disturbing against the traffic direction of breadth 2 and further improve the heat transmission in the breadth processing gap 8 through this measure.

Fig. 2 shows a kind of calender equipment, and this calender equipment has two roller stackings of arranging successively along the traffic direction front and back of breadth 2 of calender 1.Thus can be in both sides smooth breadth 2.Shown in calender equipment in, at first that the breadth downside is smooth and then that the breadth upside is smooth in the roll gap of the second roller stacking in the roll gap of the first roller stacking.Specific electric load in the temperature of heatable roller 4.1,5.2 and two the roller stackings can be regulated with being independent of each other.Dual character (fineness that the breadth both sides different) minimum of breadth 2 can be made thus, perhaps if necessary, also dual character can be regulated pointedly about smooth result.As replacement, also can at first smooth breadth upside.

Fig. 3 shows multiple roll crack calender, and this calender has a plurality of heatable hard intermediate calender rolls 5.1,5.3, and all less than the diameter of upper end roller 4.1, this upper end roller limits the border of first roll gap 3 to its diameter.Be equally applicable to optional embodiment, wherein, bottom roller 4.2 limits the border of first roll gap 3.Correspondingly in addition be applicable to above-mentioned form of implementation.The quantity of the quantity of roll gap and the roller that forms roll gap is confirmed through the fineness of paper web to be achieved 2.Fig. 3 shows the roller stacking that has six rollers.Alternatively, the roller stacking also can comprise 8 or 10 rollers.

According to the unshowned embodiment of another kind, extra breadth can be set on heatable intermediate calender rolls 5.2,5.4 handle the gap.

In the above embodiments, be with 14 can handle 8 outsides, gap at breadth and be cooled.The position of cooling can be arranged on in 14 the backhaul zone.

Claims

1. calender (1) that is used for smooth paper web (2), said paper web especially is made up of the paper that can supply intaglio printing, and this calender has at least one roller stacking, and this roller stacking has a upper end roller and a bottom roller (4.1 respectively; 4.2) and some intermediate calender rolls (5.1,5.2,5.3,5.4); In two end rollers (4.1) one limits the border of first working clearance (3) of roller stacking according to the guiding of said paper web (2), and, be used to form can load, form is the roller (4.1,4.2 of the working clearance of soft roll gap; 5.1,5.2,5.3,5.4) and be hard roller (4.1; 5.2,5.4) and soft roller (5.1,5.3,4.2); It is characterized in that the end rollers (4.1) that limits (3) border of said first working clearance is heatable hard roller, its diameter is greater than heatable hard intermediate calender rolls (5.2; 5.4) diameter, and its outer wall (9) forms the breadth be arranged in (3) front of said first working clearance and handles one of two contact-making surfaces (9,10) in gap (8); And another contact-making surface (10) is formed by the band (14) that is looped around on the guide roller (11,12,13).

2. calender as claimed in claim 1 (1) is characterized in that, said breadth is handled gap (8) and extended along the angle that holds of heatable hard end rollers (4.1).

3. according to claim 1 or claim 2 calender (1) is characterized in that, said around band (14) on rubber-like surface towards the side of said paper web (2).

4. like the described calender of one of claim 1 to 3 (1), it is characterized in that said guide roller (11,12,13) control is used for handling at breadth the band stress of the band (14) of gap (8) pressure-loaded.

5. like the described calender of one of claim 1 to 4 (1), it is characterized in that, the diameter of end rollers (4.1) that limits (3) border of said first working clearance at 1.2m in the scope of 2.0m.

6. like the described calender of one of claim 1 to 5 (1), it is characterized in that the diameter of said heatable hard intermediate calender rolls (5.2,5.4) is in the scope of 0.6m to 1.2m.

7. like the described calender of one of claim 1 to 3 (1), it is characterized in that the elastic surface of said band (14) is processed by the material that thermal conductivity is less than or equal to 10W/mK.

8. like the described calender of one of claim 1 to 7 (1); It is characterized in that; At least one guide roller (11,13) is designed to hold-down roller, and this hold-down roller is handled breadth (2) in the gap (8) at breadth and compressed through extra radial pressure load on rotation direction along portion's section.

9. like the described calender of one of claim 1 to 8 (1), it is characterized in that the contact path of adhering to contact between the outer wall (9) of said heatable end rollers (4.1) and the surface of said paper web (2) is arranged in breadth at entrance side and handles gap (8) before.

10. like the described calender of one of claim 1 to 9 (1), it is characterized in that said calender (1) has two roller stackings, they have a breadth in first working clearance (3) front respectively and handle gap (8).

11. calender as claimed in claim 10 (1) is characterized in that, in a roller stacking, upper end roller (4.1) limits the border of first working clearance (3), and in another roller stacking, bottom roller (4.1) limits the border of said first working clearance (3).

12. like the described calender of one of claim 1 to 11 (1), it is characterized in that, the length of said soft roll gap as first working clearance (3) between the 3mm to 40mm.

13., it is characterized in that all rollers (4.1,4.2,5.1,5.2,5.3,5.4) have own analog line driver like the described calender of one of claim 1 to 12 (1).

14., it is characterized in that the roller of said roller stacking is vertical, level or stacking obliquely like the described calender of one of claim 1 to 13 (1).